1. Format for non-filers of return is prescribed in GST-3 where return to be filed within 15 days from receipt of notice.
2. Format for communication of mismatch cases is prescribed in GST-ITC-1 regarding acceptance, discrepancy and duplication of ITC claim.
3. GSTR-1 can be finalized only after taking impact of auto drafted return of GSTR-1A which means-

i. Our outward supply tax liability ascertainment is finalized only after receipt confirmed by recipient or our final supply qty will be considered based on receipt qty accepted by recipient.ii. For example if X has shown 10 Mt qty in GSTR-1 and recipient has accepted/received 9 Mt only accordingly auto drafted GSTR-1A will show 9 Mt which either supplier has to accept or get it corrected from recipient within time to ascertain final tax liability.iii. I means supply qty is having link with qty received and accepted by recipient.iv. All supplier has to make proper mechanism for timely validation of outward supply qty, value from recipient in same month to avoid any mismatch and adjustment in subsequent month by way of debit note or credit note.

5. GSTR-9 Annual Return with 9B having following summary of annexures.

1. Detail of supplies and corresponding taxes2. Total outward supplies3. Total inward supplies4. Total tax liability on output supply and supplies liable to reverse charge5. Input tax credit availed during the year6. Payment of tax liability on output supply and supplies liable to reverse charge.7. By utilising cash in cash ledger8. By utilising input tax credit ledger10.Deposit by challans11.Transfer of TDS from Deductors12. Retunds13. Amounts paid under protes/as pre-deposit against demand14. Balance as on date of financial statements (GST payable)15. Balance as on date of financial statements (ITC)16. TDS deducted

Having voluminous requirement of uploading of invoice wise detail of outward supply and validation of inward supply following check list can be followed for ensuring 100% compliance under GST.

1. Return are reconciled with annual report, balance sheet through robust ERP IT system.
2. All advances also to be matched with reference ID and reverse charge cases matches.
3. Annual return contain 12 annexure pertains to reconciliation to be matched with annual return.
4. All credit booked under capital goods credit are part ot capitalization means part of fixed asset register or not.

From above details it is clear that all business houses have to design their accounting system and SAP and Oracle system in such a way that required information from filing monthly and annual return received from system and reconciliation statement of all outward supply and inward supply received matches with audited annual accounts.